29097-44-7Relevant academic research and scientific papers
Copper-catalyzed [2+3]-annulation of N-H imines with vinyl azides: Access to polyaryl 2: H -imidazoles
Zhu, Zhongzhi,Lin, Hanze,Liang, Baihui,Huang, Junjie,Liang, Wanyi,Chen, Lu,Huang, Yubing,Chen, Xiuwen,Li, Yibiao
supporting information, p. 5621 - 5624 (2020/06/19)
A practical method for the synthesis of 2H-imidazoles via a [2+3] annulation of N-H imines with vinyl azides using a copper catalyst is developed. In this conversion, environmentally friendly oxygen is used as the sole oxidant and N2 and H2O are the only by-products. The catalytic transformation, operating under mild conditions, is operationally simple and is considered as a readily available catalytic system having good substrate and functional compatibility with high atom-efficiency without the need for additional ligands or additives.
Scandium(III) Triflate Catalyzed Direct Synthesis of N-Unprotected Ketimines
Hirazawa, Yoshinobu,Kadota, Tetsuya,Kondo, Yuta,Morimoto, Hiroyuki,Morisaki, Kazuhiro,Ohshima, Takashi
supporting information, p. 120 - 125 (2020/02/20)
N-Unprotected ketimines are useful substrates and intermediates for synthesizing valuable nitrogen-containing compounds, but their potential applicability is limited by the available synthetic methods. To address this issue, we report a scandium(III) triflate catalyzed direct synthesis of N-unprotected ketimines. Using commercially available reagents and Lewis acid catalysts, ketones were directly transformed into the corresponding N-unprotected ketimines in high yields with broad functional group tolerance, even in multigram scales. The reactions were readily applicable for one-pot synthesis of important compounds such as a glycine Schiff base without isolation of N-unprotected ketimine intermediates. Preliminary mechanistic studies to clarify the reaction mechanism are also described.
Hydrogen bond directed aerobic oxidation of amines via photoredox catalysis
Wang, Hongyu,Man, Yunquan,Wang, Kaiye,Wan, Xiuyan,Tong, Lili,Li, Na,Tang, Bo
supporting information, p. 10989 - 10992 (2018/10/08)
An application of H-bonding interactions for directing the α-C-H oxidation of amines to amides and amino-ketones catalyzed by an organic photocatalyst is reported. The high efficiency of this method is demonstrated by the aerobic oxidation of pyrrolidines, diarylamines and benzylamines bearing urea groups with high yields and a wide substrate scope.
Expansion of the Substrate Specificity of Porcine Kidney D-Amino Acid Oxidase for S-Stereoselective Oxidation of 4-Cl-Benzhydrylamine
Yasukawa, Kazuyuki,Motojima, Fumihiro,Ono, Atsushi,Asano, Yasuhisa
, p. 3500 - 3505 (2018/08/06)
Discovery and development of enzymes for the synthesis of chiral amines have been a hot topic for basic and applied aspects of biocatalysts. Based on our X-ray crystallographic analyses of porcine kidney D-amino acid oxidase (pkDAO) and its variants, we rationally designed a new variant that catalyzed the oxidation of (S)-4-Cl-benzhydrylamine (CBHA) from pkDAO and obtained it by functional high-throughput screening with colorimetric assay. The variant I230A/R283G was constructed from the variant R283G which had completely lost the activity for D-amino acids, further gaining new activity toward (S)-chiral amines with the bulky substituents. The variant enzyme (I230A/R283G) was characterized to have a catalytic efficiency of 1.85 s?1 for (S)-CBHA, while that for (R)-1-phenylethylamine was diminished 10-fold as compared with the Y228L/R283G variant. The variant was efficiently used for the synthesis of (R)-CBHA in 96 % ee from racemic CBHA by the deracemization reaction in the presence of reducing agent such as NaBH4 in water. Furthermore, X-ray crystallographic analysis of the new variant complexed with (S)-CBHA, together with modelling study clearly showed the basis of understanding the structure-activity relationship of pkDAO.
Introducing Glycerol as a Sustainable Solvent to Organolithium Chemistry: Ultrafast Chemoselective Addition of Aryllithium Reagents to Nitriles under Air and at Ambient Temperature
Rodríguez-álvarez, María J.,García-álvarez, Joaquín,Uzelac, Marina,Fairley, Michael,O'Hara, Charles T.,Hevia, Eva
, p. 1720 - 1725 (2018/01/27)
Edging closer towards developing air and moisture compatible polar organometallic chemistry, the chemoselective and ultrafast addition of a range of aryllithium reagents to nitriles has been accomplished by using glycerol as a solvent, at ambient temperature in the presence of air, establishing a novel sustainable access to aromatic ketones. Addition reactions occur heterogeneously (“on glycerol conditions”), where the lack of solubility of the nitriles in glycerol and the ability of the latter to form strong intermolecular hydrogen bonds seem key to favouring nucleophilic addition over competitive hydrolysis. Remarkably, PhLi exhibits a greater resistance to hydrolysis working “on glycerol” conditions than “on water”. Introducing glycerol as a new solvent in organolithium chemistry unlocks a myriad of opportunities for developing more sustainable, air and moisture tolerant main-group-metal-mediated organic synthesis.
